Hydraulically actuated timber shear



Feb. 25, 1964 R. w. LARSON HYDRAULICALLY ACTUATED TIMBER SHEAR Filed May 31, 1961 INVEN TOR. 205322 W. lAzs'azv ATTOP/V United States Patent 3,122,184 HYDRAULICALLY ACTUATED TIMBER SHEAR Robert W. Larson, Ashland, Wis, assignor to Beloit Corporation, Beloit, Wis, a corporation of Wisconsin Filed May 31, 1961, Ser. No. 113,816 11 Claims. (Cl. 144-34) This invention relates to shears and more particularly to a powered heavy-duty timber shear.

An important object of this invention is to provide a means for cutting standing trees as well as the simultaneous cutting of one or more pieces of fallen timber in a more expedient and efficient manner than is accomplished by present day methods.

Another important object of this invention is to provide a timber shear as described above which has low operating costs and a minimum maintenance cost.

A further object is to provide a timber shear as described above having a balanced force exerting means whereby to avoid high twisting torques which would otherwise be harmful.

These and other objects and advantages of my invention will more fully appear from the following description, made in connection with the accompanying drawing, wherein like reference characters refer to the same or similar parts throughout the several views and in which:

FIGURE 1 is a perspective view of my timber shear;

FIGURE 2 is a slightly enlarged side view of my timber shear with a tree positioned therein;

FIGURE 3 is a reduced size top View with a portion of the top thereof removed for exposure of the principal elements in relation to a piece of timber; and

FIGURE 4 is an enlarged face view of an alternate form of shearing blade with portions not necessary to a full understanding of the alternate form broken away.

Of recent advancement in the problem of tree cutting has been the chain saw which has increased in popularity among the lumber industries as well as small volume lumber dealers. Although the chain saw has simplified and speeded up lumber cutting substantially, there nevertheless are existing drawbacks to this form of cutting. Some of these drawbacks are faulty and unreliably operating engines, flexible chains which are constantly subject to wearing out, stretching and frequent dulling, to say nothing of the potential hazard involved with a cutting chain which operates at a very high rate of speed.

In attempting to alleviate the undesirable features of the prior art lumber saws, I have devised a means for cutting trees in as little as one-tenth of the time of a conventional saw and, at the same time, with a maintenance cost comparatively negligible. My timber shear, which I have proven by actual use, accomplishes all the objectives of a chain saw but without the need for constantly sharpening the cutter chain teeth. I have also eliminated the faulty and often troublesome engine of the chain saw by using a separate power source independently mounted.

Referring now more particularly to the drawing, FIG- URE 1 shows my timber shear referred to generally as 19, comprised of the main elements, a frame 11, a blade assembly 12, a hydraulic power system 13 (FIGURE 2), and a bearing assembly 14.

The frame consists of an upper frame mounting 15 having a U-shape, as shown in FIGURE 1, and a lower frame mounting 16, having identical configuration to that of the upper frame 15 and correspondingly positioned, and a rear plate 17 to which the upper 15 and lower 16 frame mountings are secured. The U-frame mountings have a rear or bridging portion 18 and two forward stub or leg portions 19 for protecting the working elements as well as providing a cradle support for the timber being cut as will subsequently become apparent.

Interposed between the upper 15 and lower 16 mount- "ice ings is the blade assembly 12 consisting of an offset cam or knife 20 fixedly secured to upstanding sleeve 21. Crank lever or lever arm 22 is also fixedly secured to sleeve 21 as shown in FIGURE 2. Sleeve 21 has a bore 23 for receiving a high strength sleeve shaft 24 journaled therethrough. High strength sleeve shaft 24 is in turn journaled through, and secured to, the upper and lower frame mountings by means of head 25 and nut 26. Interposed between the upper and lower frame mountings 15 and 16 and the sleeve 21 are collars 27.

As will be noticed in FIGURE 3, the blade edge 28 adjacent the tree 29 has a sharpened portion 36 which is made of hard tool steel. With this type of material forming the cutting edge, a sharp edge will last a considerably long time considering the material it must withstand during cutting operations.

Also rigidly held in abutment between the upper and lower frame mountings is the bearing assembly 14 which has, interfitting over a bearing shaft 31, two spacers 32 which in turn interfit between the frame mountings 15 and 16 and the outer ends of pivot bearing 33. The opposite ends of pivot bearing 33 are in abutting relation to bearing post 34. As shown in FIGURE 2, bearing post 34 is fixedly attached to the rear plate 17 intermediate the two frame mounting joints 35 and 36. Securing bearing shaft 31 to the frame mountings 15 and 16 are head 37 and nut 33.

Interposed between the bearing assembly 14 and the blade assembly 12 are hydraulic cylinders 39 having hydraulic cylinder rods 4t; extending from the end 41 thereof, the outer end 3-2 of said cylinder rods 4d being fixedly secured to crank bearings 43. Located on the external surface of hydraulic cylinders 39 are hydraulic hose fittings 44 to which an external powered source, not shown, is connected.

Crank bearings 43 are in turn pivotally engaged about crank shaft .5 and in abutting relation to collars 46 and crank bushing 47.

As shown in FIGURE 2, the crank bushing 47 is secured within openings 48 in crank levers 22 opposite the sleeve 21 end. Crank shaft 45 is also made of a high strength material as is hearing shaft 31. Crank shaft 45 is secured to the ends of crank levers 22 by head 49 and nut '50.

As may be seen in FIGURES l and 3, the two stubs 19 and rear portion 18 of the upper and lower frame mountings, 15 and 16, form a cradle 51 for receiving the timber or tree 29 to be cut. The cradle 51 is formed by flat cradle plates 52 which define a configuration adapted to the circular periphery of a tree (see particularly FIG- URE 3). The cradle plates provide a shield for the shearing elements from the tree so as, for example, to keep bark and other foreign matter away from the moving parts during operation. The cradle portion of the upper and lower frame mountings 15 and 16 provide a bearing surface 53 to which the tree 29 is pressed during the shearing operation when the blades are moved inwardly and rearwardly by the hydraulic power system 13 as will be explained.

As mentioned above, the sleeve shaft 24 preferably is a high strength steel considering the forces necessary to cause the blade 2% to shear a tree 29. It is also necessary that the other elements are also constructed of a high st ength steel to withstand the high structural stresses and strains. I have found that by providing the blade 20 with a tool steel edge 30, that once sharpened it will withstand many cuiting operations before sharpening is again required.

Shown in FIGURE 4 is an alternate form of shearing edge with which the blade may be provided. Here, teeth 54, which are particularly positive in their gripping action on the tree 29, are found to have a more positive resultant 9 as shearing characteristic. Again, as above, the toothed edge 55 is made from tool steel which is Welded to the blade 2%.

I have further found that, depending on the size of wood to be cut, different modes of shearing may be desirable, for example larger trees having a larger volume require a larger blade. I have found that, with the larger blades, instead of going over center, as do the smaller blades, the desired shearing action may be accomplished merely by the blades just meeting at the center.

In the use and operation of my invention, the timber shear would be mounted on the front end of a tractor or other form of mobile equipment for transporting through a woods. The timber shear would be fastened by means of the rear plate to the vehicle, whereby the vehicle may then be driven forwardly through the woods until the timber shear is ultimately positioned against a tree. At the same time, the mobile source could carry the power source for actuating the hydraulic cylinders.

Once the timber shear is butted up against the tree so that the tree rests in the cradle portion of the shear, the hydraulic system is then energized whereby to force the hydraulic cylinder pistons outwardly thereupon actuating the crank end of the crank lever 22 which in turn forces the blade 26 to be moved inwardly upon the tree 2% and through opposing actions of the blades 2ft commence to shear the tree much as a pair of scissors would shear a piece of paper. It will be noticed with reference to FIGURE 3 that the final cutting action of the blade will be rearwardly toward the cradle 51. Since the cradle 51 is provided with the bearing surfaces 53 on the upper and lower frame mountings 15 and 16, the blade 26 will then have a bearing surface to work against as the final part of the tree is sheared.

Once the tree is sheared, the operator may simply back the timber shear away from the stump and, in like manner, continue on to the next tree.

As mentioned above, my timber shear is well adapted for cutting either a single piece of standing timber or several pieces of fallen timber. When shearing fallen timber, the shear may be positioned so as to vertically descend upon one or more pieces of timber whereby the blades may thereafter be energized as described above causing the cutting action to take place through a vertical plane.

It will, of course, be understood that various changes may be made in the form, details, arrangements and proportions of the parts without departing from the scope of my invention as set forth in the appended claims.

What is claimed is:

1. A timber shear comprising two spaced U-frame mountings having their respective leg portions and bridging portions correspondingly positioned, said bridging portions providing a pressure cradle for receiving timber to be cut, a pair of blade assemblages each mounted between corresponding leg portions of said U-frame mountmountings having their respective leg portions and bridging portions correspondingly positioned, said bridging portions providing a pressure cradle for receiving timber to be cut, a pair'of blade assemblages each mounted between corresponding leg portions of said U-frame mountings, said pair of blade assemblages having opposed cam blades pivotally mounted intermediate their ends for convergent and divergent'movement in substantially the same plane, one of said ends of said blades having a cutting edge, the

other of said ends providing a lever arm, and extensible and retractable means between said U-frmne mountings and connected to said lever arms and adapted to swing them and effect correspond ngly convergent movement of said blades whereby to shear timber when positioned against the pressure cradle of said U-frame mountings.

3. A timber shear comprising a frame having two U-frame mountings secured thereto forming recesses for the reception of timber therein, one being disposed above the other in parallel relation, a pair of blade assemblages mounted between said frame mountings, said blade assemblages having opposing offset cam blades swingably mounted for horizontal movement toward each other about spaced axes located so as to urge the timber against the closed ends of said recesses, bearing assemblages ver tically secured between said U-frame mountings, and a pressure system disposed between each of said bearing assemblages and said blade assemblages whereupon by increasing pressure of said pressure system said cam blades will forcefully converge toward each other in shearing relation.

4. A timber shear comprising a frame having an upper U-frame mounting and a lower U-frame mounting and a rear plate secured to said U-frame mountings, a pair of blade assemblages mounted between said upper and lower frame mountings, each of said blade assemblages having a sleeve abutting endwise said frame mountings, a pair of opposing offset cam blades swingably mounted on said sleeves for hor'montal movement toward each other about laterally displaced axes spaced forwardly from the closed ends of said U-shaped mountings, one of said blades being positioned to overlap the other of said blades, a bearing assembly having a shaft journaled through said upper and lower U-frarne mountings, and a hydraulic pressure system interposed between said bearing assemblages and said blade assemblages whereby said blades will be actuated toward each other in overlapping relation upon supplying pressure to said hydraulic pressure systems.

5. A timber shear comprising a frame having an upper horizontal U-shaped frame mounting and a lower horizontal U-shaped frame mounting, said U-shaped mountings having a rear portion and a pair of forward stub portions, 2. rear plate secured to said U-frame mountings at their rear portions thereof, a pair of sleeves vertically disposed between corresponding stub portions of said upper and lower frame mountings, a shaft journaled through each of said sleeves and into said U-frame mountings for securement thereto, a pair of blade assemblages having opposing offset cam blades fixedly secured to said sleeves for horizontal movement and disposed between corresponding stub portions of said upper and lower frame mountings, a pair of bearing assemblages vertically positioned between said U-frame mountings at the rear portions thereof, and a pair of hydraulic pressure systems disposed between said bearing assemblages and said offset cam blades for forceful movement of said blades toward each other.

6, A timber shear as described in claim 4 wherein said blades are positioned on said sleeves at substantially the same vertical distance from said U-frame mountings whereby when activated by said pressure system said blades will converge in confronting relation to each other so as to meet in the center of said timber shear.

7. A timber shear as described in claim 4 wherein the leading edge of said pair of opposing cam blades is sharpened with a smooth continuous edge.

8. A timber shear as described in cla'un'4 wherein the leading edge of each of said pair of opposing cam blades has a sharpened toothed configuration.

9. A timber shear comprising a pair of vertically spaced U-shaped members each having leg portions for straddling timber and a bridging portion forming a bearing surface for said timber, a pair of blades pivotally mounted between said U-shaped members on vertical axes located in a spaced relationship with each other and said bridging 5 5 portions such that when said blades are pivoted toward 11. A timber shear as described in claim 9 in which the said timber their cutting edges will engage the sides of cutting edges of said blades are curved.

the timber to press said timber against the bearing surfaces formed by said bridging portions, and hydraulic References Clted m the file of thls patent means for actuating said blades to cause pivotal movement 5 UNITED TES PATENTS thereof toward said timber- 2,529,934 Gracey et a1 Nov. 14, 1950 10. A timber shear as described in claim 9 in which said 2, 97 459 p n Dec. 1 1954 axes intersect said leg portions at locations intermediate said bridging portions and the free ends of said leg por- FOREIGN PATENTS tions. 10 399,207 Italy Apr. 15, 1936 

9. A TIMBER SHEAR COMPRISING A PAIR OF VERTICALLY SPACED U-SHAPED MEMBERS EACH HAVING LEG PORTIONS FOR STRADDLING TIMBER AND A BRIDGING PORTION FORMING A BEARING SURFACE FOR SAID TIMBER, A PAIR OF BLADES PIVOTALLY MOUNTED BETWEEN SAID U-SHAPED MEMBERS ON VERTICAL AXES LOCATED IN A SPACED RELATIONSHIP WITH EACH OTHER AND SAID BRIDGING PORTIONS SUCH THAT WHEN SAID BLADES ARE PIVOTED TOWARD SAID TIMBER THEIR CUTTING EDGES WILL ENGAGE THE SIDES OF THE TIMBER TO PRESS SAID TIMBER AGAINST THE BEARING SURFACES FORMED BY SAID BRIDGING PORTIONS, AND HYDRAULIC MEANS FOR ACTUATING SAID BLADES TO CAUSE PIVOTAL MOVEMENT THEREOF TOWARD SAID TIMBER. 